SIRT1 and preeclampsia: In addition, the expression of serum SIRT1 was decreased in patients with preeclampsia combined with fetal growth restriction compared with the combined group (p < 0.0001) (Figure 2(a)); the peak-to-trough ratio of arterial blood flow velocity, the pulsatility index, and the resistance index were all increased in patients with preeclampsia combined with fetal growth restriction compared with the uncombined group (p < 0.0001) (Figures 2(b)–2(d)).